More From American Greed: The Fugitives

Nine people who committed shocking cybercrimes

In July 2013, the Center for Strategic and International Studies released a report called "The Economic Impact of Cybercrime and Cyber Espionage." It said that this activity costs the global economy between $300 billion and $1 trillion. Why is an exact figure so hard to pin down?

"Companies conceal their losses and some are not aware of what has been taken," the report said. "Intellectual property is hard to value. Some estimates relied on surveys, which provide very imprecise results unless carefully constructed. ... These problems leave many estimates open to question."

While cybercrime represents billions of dollars in losses to businesses and consumers, committing it requires very little overhead. Some who stole millions were able to do so from the parking lot of a big box store. And it doesn't require years of experience to cause damage either—some notorious hackers committed their crimes when they were not even old enough to buy beer.

Read ahead to see CNBC.com's list of cybercriminals who stole millions of dollars and hacked their way into systems that even the experts thought were secure.

By Daniel BukszpanPosted 23 Oct. 2013

CNBC follows the money trail in search of the most wanted white-collar fugitives."American Greed: The Fugitives," Thursdays at 10 p.m. ET.